Steam injector for internal-combustion engines



E. DRYDYKE Feb. 15, 1955 STEAM INJECTOR FOR INTERNAL-COMBUSTION ENGINESFiled Nov. 2. 1950 Na Q F034 Ix m ATTOPNAY'I.

United States Patent STEAM INJECTOR FOR INTERNAL-COMBUSTION ENGINESEugene Drydyke, Milwaukee, Wis.

Application November 2, 1950, Serial No. 193,605

4 Claims. (Cl. 123-25) This invention relates to steam injectors forinternal combustion engines.

It is well known that combustion in internal combustion engines may bematerially improved by the addition of small amounts of vapor or steamto the gaseous fuel mixture. Such additions in proper proportions andunder proper conditions impart a desirable anti-knock quality to thefuel and tend to avoid and to eliminate objectionable carbon depositswithin the engine.

Many devices have been proposed for this purpose but, as heretoforedesigned, none have proven entirely satisfactory and none are in generaluse. Many such devices are too complicated and expensive to justifytheir existence and many are incapable of properly proportioning theadded steam under various conditions of engine operation, Inability tosupply adequate quantities of steam renders such devices ineffective,while additions of steam in excessive amounts, or containing appreciableamounts of free water, impairs combustion and results in ill effects onthe engine.

One object of the present invention is to provide a steam injectorcapable of introducing into the fuel mixture properly proportionedquantities of water-free steam under various conditions of engineoperation. This I have accomplished by providing a steam reservoir inwhich is maintained an adequate supply of water-free steam atsubstantially constant pressure, preferably atmospheric pressure, andfrom which the steam is led and directed into the engine intake manifoldthrough a nozzle projecting thereinto, the flow through the latter beinginduced by the suction or sub-atmospheric pressure within the manifoldand being controlled largely by the size of the nozzle dischargeorifice. Provision is also preferably made to automatically compensateat least in part for the varying conditions that normally occur withinthe intake manifold under various conditions of engine operation.

Other more specific objects and advantages will appear, expressed orimplied, from the following description of a steam injector constructedin accordance with the present invention.

An illustrative embodiment of the present invention is shown in thesingle figure of the accompanying drawing.

The steam injector shown includes a suitable boiler formed by a jacket11 welded to and encircling a portion of the exhaust pipe or manifold 12of an internal combustion engine. Water is supplied to the boiler 10preferably from a supply tank 13 through suitable tube or pipeconnections 14 and 15 and an interposed float valve 16.

The float valve functions to maintain the water in the boiler 10 at asubstantially constant level, such that the boiler is about one quarterfull. Although this valve may assume various forms, in this instance itcomprises a closed housing 16, having a top vent 17, and connected tothe bottom of the boiler 10 through the connection 15. The connection 14from the supply tank 13 leads to a fitting 18 in the top of the housing16 containing a needle valve 19 that controls admission of water to thelatter. The needle valve 19 is shown loosely seated in a depression 20formed in the upper end of a suitable float 21 which is loosely guidedby bails 22 for free vertical movement within the housing 16. Lack of apositive connection between the valve 19 and float 21 assures a freeaction of the valve in the fitting 18, this condition being furtherenhanced by the lubricating effect of water contained in the depression20. It will of course be understood that the valve 19 is opened by thepressure of the supply water and 2,702,027 Patented Feb. 15, 1955controlled by the rise and fall of the float 21 in the housin 16.

A suitable connection 23 provides communication between the upper end ofthe boiler 10 and a steam reservoir 24. The reservoir shown comprises asubstantially cylindrical housing, preferably slightly tilted, andequipped at its lower end with a drain orifice 25 for the escape ofwater of condensation. The connection 23 is preferably arranged to admitsteam from the boiler 10 to the lower end of the reservoir.

The capacity of the boiler 10 is such as to maintain the reservoir 24filled with steam under all operating conditions, and the latter ispreferably vented so as to maintain the contained steam at approximatelyatmospheric pressure. In this instance venting is effected by a tube 26projecting through the top of the reservoir and covered by an open-sidedhood 27 preferably filled with a suitable filter material such as steelwool, glass wool or the like.

A steam conductor tube 28 leads from the upper end of the reservoir 24to a discharge nozzle 29 arranged to direct the steam into the fuelmixture passing through the intake manifold 30 of the engine. The nozzle29 is shown mounted in and projecting through the side of the manifoldand terminating in a restricted orifice 31 disposed substantiallycentrally of the latter, so as to effect an intimate mixture of thedischarged steam with the passing fuel mixture.

The fuel conductor tube 28 is preferably of a size to provideunrestricted flow of steam to the nozzle 29, this flow being induced bythe suction or sub-atmospheric pressure within the manifold, and therate of flow being governed largely by the size of the nozzle orifice31. To compensate for the wide variations in manifold suction resultingfrom changes in engine throttle positions, provision is made forautomatically regulating the rate of admission of steam from thereservoir 24 to the steam conductor tube 28. For this purpose thereservoir shown is equipped with a butter-fly valve 32.

In this instance the valve 32 is rockably supported within the reservoir24 and so arranged that when closed, it separates the upper end from theremainder of the reservoir. It is yieldably urged toward closed positionby a suitable spring 33, that being the position assumed when the engineis idling at closed throttle position, and in that position little or nosteam enters the fuel mixture. Valve 32 is controlled by a lever arm 34connected through appropriate linkage 35 to the control lever 36 of theengine throttle, one end of the link 35 being engaged in a short slot 37provided in the lever 36, so as to provide a lost-motion connectiontherebetween. The arrangement is such that as the throttle lever 36 isswung toward the left from the closed-throttle position shown, the slot37 permits the valve 32 to remain in closed position until the throttlehas been moved from an iding position to a running position, andthereafter the valve 32 opens to an extent substantially correspondingto that of the throttle.

For the purpose of conserving steam and the supply water, provision ispreferably made for withdrawing excess steam from the boiler 10,condensing the same, and returning the water of condensation to theboiler. In this instance a hollow fitting 38 containing a suitable handcontrolled valve 39 is attached to the boiler, well above the waterlevel therein, and steam escaping through the valve is conducted througha tube 40 to a suitable condenser 41, the water of condensation beingreturned to the boiler through a tube 42 communicating with the watersupply connection 15. Water of condensation escaping from the steamreservoir 24 through the drain orifice 25 is also returned to the boilerthrough a connection 43 between the orifice and the tube 40. The fitting38 is preferably disposed well below the connection 23 in order that itmay serve to carry away any water-laden bubbles that normally rise abovethe water in the boiler, to thereby intercept and prevent entry of suchbubbles into the steam reservoir 24 through that connection 23.

From the foregoing it will be noted that a steam reservoir 24 has beenprovided which is maintained filled with steam at substantiallyatmospheric pressure; that the reservoir steam is devoid of free water,since it is supplied from the top of a boiler in which the water ismaintained at a low level, and since any water of condensation occurringin the reservoir is promptly discharged through the drain port 25; thatthe tube 28 provides a clear and ample passage for the steam from thereservoir 24 to the discharge nozzle 29 free from any possibleobstruction by water of condensation or otherwise; and that the steam,thus delivered to the nozzle, is directed through the nozzle orifice 31into the passing fuel mixture at a point to insure an intimate mixingtherewith and at a rate determined largely by the size of the orifice.It will be further noted that the valve 32 contained within thereservoir 24 func tions automatically to cut off the supply of steam tothe tube 28 and nozzle, when the engine is idling, and when the suctionin the manifold is at a maximum, and to progressively clear the path ofsteam flow to the tube and nozzle as the engine throttle is opened andthe suction in the manifold correspondingly reduced.

Various changes may be made in the embodiment of the inventionhereinabove specifically described without departing from or sacrificingthe advantages of the invention as defined in the appended claims.

I claim:

1. A steam injector for use in conjunction with an internal combustionengine including a throttle control, said injector comprising a steamreservoir including venting means for maintaining the same atatmospheric pressure, a steam boiler operatively associated with theexhaust pipe of the engine and connected to said reservoir to supply thesame with live steam, connecting means associated with said reservoirand the intake manifold of the engine to deliver steam from saidreservoir to the intake manifold, a valve disposed in said reservoir forcontrolling the release of steam from said reservoir to said intakemanifold, yieldable means for normally maintaining said valve in closedposition, and an operating means associated with said valve and thethrottle control, said last named means being responsive to movement ofthe throttle control to regulate the admission of steam from saidreservoir to the intake manifold.

2. A steam injector for use in conjunction with an internal combustionengine including a throttle control, said injector comprising a steamreservoir including venting means for maintaining the same atatmospheric pressure, a steam boiler operatively associated with theexhaust pipe of the engine and connected to said reservoir to supply thesame with live steam, connecting means associated with said reservoirand the intake manifold of the engine to deliver steam from saidreservoir to the intake manifold, a valve disposed in said reservoir forcontrolling the release of steam from said reservoir to said intakemanifold, yieldable means for normally maintaining said valve in closedposition, and operating means including a lostmotion disposed betweensaid valve and the throttle control, said operating means beingresponsive to movement of the throttle control to regulate the operationof said valve and said lost-motion connection providing the meanswhereby the opening of said valve in response to movement of saidthrottle control is delayed to preclude the admission of steam to theintake manifold until the speed of the engine exceeds its normal idlingspeed.

Cit

3. A steam injector for use in conjunction with an internal combustionengine including a throttle control, said injector comprising a steamreservoir including venting means for maintaining the same atsubstantial atmospheric pressure, a steam boiler operatively associatedwith the exhaust pipe of the engine and connected to said reservoir tosupply the same with live steam, connecting means associated with saidreservoir and the intake manifold of the engine to deliver steam fromsaid reservoir to the intake manifold, a valve disposed in saidreservoir for controlling the release of steam from said reservoir tothe intake manifold, yieldable means for normally maintaining said valvein closed position, operating means associated with said valve andthrottle control and responsive to movement of the throttle control toregulate the admission of steam from said reservoir to the intakemanifold, means for maintaining a substantially constant liquid level insaid boiler, and a condenser operatively associated with said steamboiler for receiving and condensing the excess of steam generated bysaid boiler over the amount required to maintain said reservoir filled.

4. A steam injector for use in conjunction with an internal combustionengine including a throttle control, said injector comprising a steamreservoir including venting means for maintaining the same atsubstantial atmospheric pressure, a steam boiler operatively associatedwith the ex aust pipe of the engine and connected to said reservoir tosupply the same with live steam, connecting means associated with saidreservoir and the intake manifold of the engine to deliver steam fromsaid reservoir to the intake manifold, a valve disposed in saidreservoir for controlling the release of steam from said reservoir tosaid intake manifold, yieldable means for normally maintaining saidvalve in closed position, operating means including a lost-motiondisposed between said va1ve and the throttle control, said operatingmeans being responsive to movement of the throttle control to regulatethe operation of said valve and said lost-motion connection providingthe means whereby the opening of said valve in response to movement ofsaid throttle control is delayed to preclude the admission of steam tothe intake manifold until the speed of the engine exceeds its normalidling speed, and a condenser operatively associated with said steamboiler for receiving and condensing the excess of steam generated bysaid boiler over the amount required to maintain said reservoir filled.

References Cited in the file of this patent UNITED STATES PATENTS

